1. Field of the Invention
This invention relates to a method and apparatus for scoring and breaking an optical fiber and, specifically, for scoring and breaking an optical fiber near a ferrule forming an end face substantially normal to the longitudinal axis of the optical fiber.
2. Description of Related Art
It is now well known to use optical fibers in a multitude of systems including telecommunication and datacommunication systems. To install such systems, many connections must be made between ends of optical fibers.
A traditional way for making a connection between ends of two optical fiber cables is as follows. First, a buffer layer is removed from several inches of each of the cables near the ends to be joined. When the buffer is removed, the remaining optical fiber comprises a core surrounded by cladding which together have an outer diameter of about 125 microns (.mu.m) which is about the diameter of a human hair. Second, each of the two thin fragile optical fibers is threaded by hand through a separate ferrule which can be either glued onto the optical fiber with, for instance, epoxy or fixed to the the optical fiber by crimping, i.e., squeezing and deforming, a portion of the ferrule firmly around the optical fiber. Traditionally, ferrules were epoxied onto the fibers. More recently, the industry is inclined to crimp ferrules on fibers because it takes significantly less time, i.e., one does not have to wait for the epoxy to dry. Third, the optical fiber extending beyond the end of each of the ferrules is cleaved, which entails scoring and breaking the optical fiber, about one diameter or 125 .mu.m beyond the end of the ferrule. Fourth, the ends of the optical fibers are polished, typically, first with a course, e.g., 12 .mu.m, grit paper until the ends extend about 20 to 25 .mu.m beyond the end of the corresponding ferrules and then with one or more finer, e.g., 1 .mu.m and/or 0.3 .mu.m, grit papers until the ends of the optical fibers are flush with the end of their corresponding ferrules. Due to the size of the optical fibers, this polishing requires the skill of an experienced individual to make an acceptable end. Finally, the ferrules are manually inserted into a connector housing assembly which is intended to position the optical fibers such that they are adjacent to one another with their optical axes in alignment with respect to each other. This is a time consuming process which requires skill and, as a result, is costly.
Further, the final condition of the ends of the optical fibers affects the power transmission capabilities of the connection. Ideally, each end has a mirror finish and is perpendicular to the longitudinal axis of the optical fiber. However, polishing of the ends of the optical fibers, especially with the courser grit paper, does result in defects, such as cracks, chips and scratches in the end faces. Such defects are very difficult to see with the natural eye and may require the above described process to be redone creating a new end face.
The cleaving process of scoring and breaking an optical fiber can produce a good break resulting in an optical fiber end that is quite smooth and substantially perpendicular to the optical fiber longitudinal axis. However, once the ferrule is attached to the optical fiber there was no tool in the prior art for cleaving the fiber substantially near the ferrule so that typical polishing can be reduced.
Efforts were made to crimp a ferrule onto a fiber that had a cleaved end so that the ferrule end and the cleaved optical fiber end would coincide in the same plane. However, the crimping caused an unpredictable shift or movement between the fiber and the ferrule such that the ends of the ferrule and the fiber were not always coincident.
It is an object of this invention to provide an apparatus for cleaving an optical fiber near a ferrule so that typical polishing can reduced.
It is an object of this invention to provide an apparatus for scoring and breaking an optical fiber near a ferrule forming an end face in the fiber substantially normal to the longitudinal axis of the fiber.
It is an object of this invention to provide an apparatus that can be used after a ferrule is connected to an optical fiber to score and break the fiber near the ferrule forming the end face substantially normal to the longitudinal axis of the fiber.